Telescoping pole



April 18, 1961 E. L. McMULLlN TELEscoPING POLE Filed Aug. 14, 1959 llllllllllll Il INVENTOR. EARL L. MCMULUNA ATTOIZNEHS te States TELESCOPING PGLE Filed Aug. 14, 1959, Ser. No. 833,843

'2 Claims. (Cl. 2S7-5S) This invention relates to a sectional, telescopic pole and, more particularly, relates to an electrically non-conductive, sectional, telescopic pole which is useful for enabling a workman to perform work from the ground on objects, such as electric power lines, located a substantial distance from the ground.

It has been previously suggested to provide sectional, telescopic poles for the above-mentioned purpose and others related thereto, but the prior art constructions have not been completely satisfactory. In particular, the prior art structures do not provide a sufficiently secure, but releasable, lock for holding the sections in extended position with respect to each other. Thus, when a sudden pushing action or more than a limited torque action is imposed on the pole for eiecting work, the prior art locks become disengaged and cause the sections to collapse.

Purther, in certain prior art constructions, no means are provided to limit the smaller sections from falling the length of the remaining extended sections when the smaller section is inadvertently jarred loose. This is a particularly severe problem since the tool which is used to perform the work is ordinarily attached to the top or smallest section and extends at least in part sidewardly therefrom. lf the top section accidentally becomes loosened, it collapses within the adjacent larger section and the tool strikes against the top end of the adjacent larger section and splits and fractures same. This renders the pole useless. '.Further, the prior art constructions have not been completely satisfactory because they are diicult to clean and repair and it is dicult to replace the sections thereof.

Accordingly, it is an object of this invention to provide an improved, sectional, telescopic pole.

It is a further object of this invention to provide an improved, sectional, telescopic pole, as aforesaid, having a positive, mechanical lock at the base of each joint, which lock can easily be engaged to lock the sections in an extended position and which can be easily disengaged for retracting the sections.

It is a further object of this invention to provide an improved, sectional, telescopic pole, las aforesaid, in which the sections and the structure providing the positive lock can be quickly disassembled for cleaning and repair of the pole, when necessary.

It is a further object of this invention to provide an improved, sectional, telescopic pole, as aforesaid, which may be used to push, pull or twist work located at a distance from the ground without danger of the pole collapsing.

It is a further object of this invention to provide an improved, sectional telescopic pole, as aforesaid, which can be easily collapsed in such a fashion that tools attached to the top section of the pole cannot strike and damage the other sections of the pole.

Other objects and advantages of the invention will become apparent to those acquainted with equipment of ,dd Patented Apr. 18, 1961 of Figure 2.

CONSTRUCTION The pole includes a plurality of elongated, round tubular sections and there is shown, in the preferred embodiment of the invention illustrated in the drawing, a pole consisting of seven sections 10, 11, 12, 13, 14, 15 and 16 of progressively smaller size. The smallest section may carry a tool T at its outer end. Preferably, the sections are slightly tapered and each section is of such internal and external diameter that it may slide for a limited distance within the adjacent larger section and, further, may receive the adjacent smaller section for limited sliding movement therewithin.

The tubular sections are rigid and electrically nonconductive and are preferably formed of a resin, such as a polyester-type resin or urea-formaldehyde-type resin, impregnated with glass fibers. Alternatively, the sections may be formed of a plurality of fiberglass fabric laminate impregnated with resin and bonded together to form a unitary structure. However, the sections may be formed of other electrically non-conductive materials without departing from the scope of the invention.

Adjacent one end, hereinafter referred to as the upper end, of each section, except the smallest section 16, the wall thickness of the section is increased by decreasing the internal ,diameter thereof to provide an internal shoulder 21 spaced a predetermined distance from the upper end of thevsection and a relatively thick-walled, end por tion 22 extending between said shoulder and the upper end of the section. The thickened end portion 22 of the section has a radially extending opening 23 therethrough located between the shoulder 21 and the upper end of the section.

A plug 24 is removably disposed in the lower end of each section, except the largest section 10. 'I'he plug 24 has a shank 25 which closely slidably tits within the lower end of the section and extends to a point located above the opening 23 of the adjacent outer section, when the two sections are extended. The plug 24 has an enlargedflange 26 located outside of the section in which it is mounted and saidenlarged flange is of suicient size that it may slide within the portion of large diameter of the adjacent outer section and may abut against the .shoulder 21 of said outer section to positively limit movement of the inner section with respect to the outer section.

The shank 25 has a transversely extending, stepped passage 28 therethrough, said passage having a shoulder 30. The passage 28 is closed at its large end thereof by a plug 37 which is preferably disposed adjacent to the wall of the section in which the plug is mounted. The small end of passage 28 is aligned with an opening 29 through the wall of the inner section adjacent the lower end thereof. The openings 23 and 29 in the inner and outer sections are alignable when the ange 26 on the plug 24 in the inner section abuts against the shoulder 21 on the outer section. e

A pin 31 having an enlarged flange 32 at the inner end thereof is disposed in passage 28 and said enlarged ange 32 is adapted to abut against the shoulder 30 of said passage to limit outward movement of said pin. 'Ihe pin 31 is of such size that it may slidably extend through openings 23 and 29 when same are aligned. A coil spring 33 is disposed between the plugi- 37 and the en larged angeSZ of the pin 31 and urges said pin outwardly until said enlarged liangeV abuts against the shoul-V der 3d ofthe YVpassagel In such position, the pin extends Vthrough the openings 29 Vand 23 in the finii'erv` and "outer sections and provides a positive mechanical lock therebetween. l u Y `'The pin 31 is provided with a partially spherical projection 36 on its outer end. The projection 36 is preferably of a height'substantially equal to the Vthickness of the outer section, but less than the thickness of Ythednner section.' When the pin 31 is vdepressed so that the? projection 36 is at the, same level as the outside surface of the outersection, the pin'll will automatically be' retracted'when the adjacent sections are turnedwith respectto each other. This materially improves the "ease of-collapsing the sections. Y

The sections preferably have Ya; slight internal'itaper from the lower to the upper end thereon( YThus; an inner section is free to slide withinthe adjacent outer section until the flange on the plug 24 therein abuts against the internal shoulder 2.1 ofsaid outersection. Desirably,`

the thickened end portion 22 of the outer section has an `internal taper which corresponds Yto the external taper position by moving same longitudinally with respect to each other until the'iiange 26 on the plug 24 on the in- Y `ner section abuts against the internal shoulder Z1 on the outer section. lfV the openings 2,9 and Z3 in the inner and outer sections, are not aligned, same may beV readily accomplished by rotating one section with respect to the other until Ysuch openings are in valignment. At that time, the spring 33 will urge the pin 31 outwardly through the aligned openings and the sections will then be locked in their extended position with respect ,to each other. Y c YRetraction of the sections may beV accomplished by rst depressing the pin 31 into the sections until the inner edge of the spherical projection 36 thereonrisat or below the same level as the interior surface of the outer `aesthetics tions. -In this way it is possible toY provide apole of anyV desired possible length merelyby removing the sections which `are not needed. This construction has, the further advantage that it permits easy` Vdisassembly of the pole for cleaning, inspection and maintenance operations.

It is further pointed out that the plug serves as a positive mechanical limit to the amount of movement of the sections with respect to each other 4not only during extension of the sections but also during collapsing thereof. For this purpose, the plugs'are made of Suicient axial Y length that a plug in one section will abut, during collapsing of thesections, against the plug in the adjacent outer section before any elements carried on the end of the inner section can forcibly contact the end of the adjacent outer section.V This Vapplies particularly to the smallest section 16V of the pole which carries lthe tool T which might otherwise cause splitting `ofthe adjacent outer section upon collapsing thereof. 1

Representative uses of the sectional, ltelescopic pole disclosed hereinabove are to performl work, such as operating switch closures for electric power lines, removing debris from the power or telephone lines, removing and replacing light Vbulbs in street lamps or high'buildings, changing fuses in fuse Vlinks or high lines, etc. Other uses to which the iriventionmay be put will be apparent to those acquainted with equipment of this type.

vWhile a particular preferred embodiment of the invention hasy been described hereinabove and illustrated in the drawings,the invention contemplates such changes or' modifications therein as lie within the scope of the appended claims.

section. Retraction of the pin maybe completed by rotating one section with respect to the other and such will cause complete retraction of the pin within the innerV section. Of course, the pin may be fully depressed ywithin the inner section manually but such is somewhat more diicult than the above-described operation.V 'Ihe two sections may then be collapsed by moving same Vaxial- What Yis claimed is:

1. A sectional, telescopic pole comprising a plurality of tapered, tubular, elongated, round sections of progressively smaller diameter which are telescopically interfitted, each section having an lend portion of internally enlarged wall thickness adjacent the small end thereof, said endV portion defining a shoulder spaced a predetermined distance from the small end thereof, said end portion having aV rst radial opening therethrough between said shoulder and'said` small end, said section Vhaving a second radial opening therethrough adjacent the large end thereof; a plug closing the large end of each Vof said sections, said'large end of each section being of slightly less diameter than the internal diameter of the adjacent outer section at the shoulder therein, said plug having a round shank extending into said large end and snugly received therein, said plug having an enlarged flange located outside of said large end, saidv iiangeY being of smaller diameter than the internal diameter of the adjacent'larger section up to the shoulder therein and being of larger diameter than said shoulder so thatrsaid ange is freely slidable within the adjacent larger section until the end of the pin rather than the spherical enlargement. The total depth of the taper would preferably be about equal `to the thickness of the wall Vof the outer section. i It is particularly pointed out that the sole Yconnection of the plugs 24 to the sections is effected by thepins 31. Consequently, each plug can be entirely removed from its section by depressing the pin 31 into the pas- Y sage 28 so that it is fully received within the plug. When the pin is fully retracted within the plug, the plug can bereasily removed by forcing same or allowing same to drop out of the lower end of the section.

v vBecause of this construction, it is readily possible to remove sections rfrom the rod, lif desired. Thus, after the plug 24has been removed from the section 11, the

Vit engages the shoulder therein, said shank having a sin- Vgle transverse passage therein transversely aligned with said second opening in said section and alignable with said iirst opening in the end portion of the adjacent outer section when the iiangeV on the plug in the inner section abuts against the shoulder of the adjacent outer section; a pin slidablyy disposed inrsaidy passage and a spring urging said pin outwardly` whereby when 4said openings are aligned said pin extends through both openings to positively mechanically lockV the sections in their extended position with respect to each other, said pin being of lesser length than said passage so that said pin may be completely received within said passage, said plug being free of other connection-to said sectionV so that it may f be entirely removed therefrom when said pin is completeadjacent outer section 10 can be removed Ythe'rt-ifrom by y sliding the sections axially with respect to each other.

flfhe other sections can be'removed in similar fashion-by removing the largest section from the remaining secly'received in said passage. Y

2. Asectional, Ytelescopic pole according to claim l wherein said pin has a spherical projection at theV outer end thereof, said projection being of a depth not substantially greater than the thickness of said end portion of the Vadjacent larger section and lless than the thickness of the inner section sothat the pin may automatically be E Q54 retracted after it is depressed to substantially the same 942,490 level as the outside surface of said larger section by rotat- 2,291,593 ing said sections with respect to each other. 2,319,992

References Cited in the file of this patent UNITED STATES PATENTS 109,297 Bushnell Nov. 15, 1870 6 Dunn .,.f Dee. 7, 1909 Hubbard July 28, 1942 Hubbard May 25, 1943 FOREIGN PATENTS France Oct. 6, 1908 

